Hatha Yoga and Executive Function: A Systematic Review

Executive Function After Yoga: Adults With Acquired Brain Injury-A Pilot Study

IMPORTANCE

Acquired brain injury (ABI) may result in deficits in executive function (EF), which affects engagement in occupations.

OBJECTIVE

To explore the impact of group yoga on EF in people with ABI.

DESIGN

Single-arm pilot study with preyoga assessments and postyoga assessments (after 8 wk of yoga).

SETTING

Yoga classes and assessments were completed within university buildings on a college campus.

PARTICIPANTS

Twelve participants with chronic ABI (>6 mo post-ABI) were recruited through convenience and purposive strategies from the local community.

INTERVENTION

An 8-wk adaptive group yoga intervention was provided by an adaptive yoga specialist. Yoga classes were 60 min and occurred once per week.

OUTCOMES AND MEASURES

EF was assessed before and after the yoga intervention using the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) self-report form. Normative data were analyzed with paired sample t tests.

RESULTS

Nine participants completed all study procedures. Results from paired sample t tests showed significant improvements on the Behavioral Regulation Index of the BRIEF-A (p = .046). No significant improvements were found on individual EF scales, the Metacognition Index, or the Global Executive Composite (ps > .05).

CONCLUSIONS AND RELEVANCE

Group-based yoga may improve some aspects of EF for adults with chronic ABI; however, further research with larger sample sizes is needed. Plain-Language Summary: Yoga, an intervention increasingly used in occupational therapy practice, may be beneficial in improving behavioral regulation (an executive function) for adults with acquired brain injury.

The influence of hatha yoga on stress, anxiety, and suppression: A randomized controlled trial

Engaging in yoga may mitigate stress and anxiety in individuals while potentially enhancing one's capacity to manage distractions. Our research aimed to explore the relation between these two outcomes: Can an eight-week yoga program foster distraction suppression, thereby reducing stress and discomfort? To answer this question, we used Hatha Yoga, the most commonly practiced form of yoga. We tested if the intervention improved participants' ability to suppress distractions and selectively decrease self-reported stress and stress reactivity. In Addition, we investigated whether such an intervention would increase participants' mindfulness. Our study included 98 healthy yoga novices between 18 and 40 years who were randomly assigned to either an experimental or a waitlist condition, with each participant completing pre- and post-intervention assessments, including questionnaires, as well as electrophysiological and behavioral measures. After eight weeks of yoga practice, significant reductions in self-reported stress and stress reactivity levels, as well as increased mindfulness, were observed among those participating in the intervention relative to those in the waitlist control group. There were, however, no significant changes in state or trait anxiety due to the intervention. Changes in stress measures could not be explained by changes in participants' ability to suppress distractors, which was not affected by the intervention. Overall, our findings suggest that regular participation in Hatha Yoga can improve mental health outcomes without impacting cognitive functioning directly related to distractor suppression. CLINICAL TRIAL REGISTRATION NUMBER: NCT05232422.

Feasibility and impact of a remote moderate-intensity yoga intervention on stress and executive functioning in working adults: a randomized controlled trial

The feasibility of a moderate-intensity yoga intervention, delivered remotely via supervised and unsupervised sessions, and its psychosocial and cognitive effects have not been thoroughly investigated. This randomized controlled trial assessed feasibility and preliminary efficacy of an 8-week moderate-intensity yoga intervention (3×/week, 50 min) delivered remotely (vs. a waitlist control arm), on stress and cognitive functioning. Participants (n = 86) were low active, full-time working adults (81.40% female; Mage = 41 years) with symptoms of stress. Feasibility was assessed via adherence, enjoyment, and safety; stress and anxiety via self-report questionnaires; and executive functioning via neuropsychological tests. Overall attendance was 75.1%, 100% of participants enjoyed the intervention, and only one adverse event was reported. At follow-up, the yoga group had significantly lower stress and anxiety, and higher accuracy on working memory tasks. Remote moderate intensity yoga practice proved safe, enjoyable, and may reduce stress and improve cognitive functioning. This study was pre-registered on ClinicalTrials.gov (NCT04740229).

Effects of Yoga and Aerobic Exercise on Verbal Fluency in Physically Inactive Older Adults: Randomized Controlled Trial (FitForAge)

Purpose

To compare the effects on verbal fluency of a supported yoga-based exercise intervention to an aerobic exercise intervention and a wait-list control group.

Participants and Methods

Eighty-two physically-inactive but otherwise healthy adults (mean age 72.5 years, range 65-85, 77% female) were recruited into a 12-week, three-group, parallel randomized controlled trial. Participants were supported to complete ≥3 Hatha yoga classes per/week or ≥3 structured aerobic exercise sessions/week. A wait-list control group continued usual daily activities only. Verbal fluency, including total-FAS, animals, and verbs, was assessed before and after interventions. Group effects were assessed using analysis of covariance (ANCOVA).

Results

Twenty-seven participants were randomized to yoga, 29 to aerobic exercise and 26 to a waitlist. At 12-week follow-up, compared to baseline, there were increases in mean total-FAS in the yoga (+5.0 words, p=0.002) and aerobic exercise groups (+6.6 words, p=0.004). Mean total-FAS in the wait-list control group remained stable (-0.5 words, p=0.838). There were medium-magnitude estimated treatment effects on total-FAS for yoga versus wait-list control and aerobic exercise versus wait-list control: Hedges' g=0.51 (p=0.213) and 0.57 (p=0.098) respectively. In addition, small-to-medium magnitude estimated treatment effects were seen on animals and verbs for yoga versus wait-list control and aerobic exercise versus wait-list control: g=0.28 (p=0.155), 0.19 (p=0.766) and 0.50 (p=0.085), 0.59 (p=0.233) respectively.

Conclusion

Participation in yoga or aerobic exercise was associated with estimated improvements in verbal fluency compared to a non-active control group. Yoga and aerobic exercise may be promising approaches by which to promote cognitive function among older adults.

Trial Registration

DRKS00015093, U1111-1217-4248.

A narrative review on yoga: a potential intervention for augmenting immunomodulation and mental health in COVID-19

Background

The ongoing novel coronavirus disease 2019 (COVID-19) pandemic has a significant mortality rate of 3–5%. The principal causes of multiorgan failure and death are cytokine release syndrome and immune dysfunction. Stress, anxiety, and depression has been aggravated by the pandemic and its resultant restrictions in day-to-day life which may contribute to immune dysregulation. Thus, immunity strengthening and the prevention of cytokine release syndrome are important for preventing and minimizing mortality in COVID-19 patients. However, despite a few specific remedies that now exist for the SARS-CoV-2virus, the principal modes of prevention include vaccination, masking, and holistic healing methods, such as yoga. Currently, extensive research is being conducted to better understand the neuroendocrinoimmunological mechanisms by which yoga alleviates stress and inflammation. This review article explores the anti-inflammatory and immune-modulating potentials of yoga, along with its role in reducing risk for immune dysfunction and impaired mental health.

Methods

We conducted this narrative review from published literature in MEDLINE, EMBASE, COCHRANE databases. Screening was performed for titles and abstracts by two independent review authors; potentially eligible citations were retrieved for full-text review. References of included articles and articles of major non-indexed peer reviewed journals were searched for relevance by two independent review authors. A third review author checked the excluded records. All disagreements were resolved through discussion amongst review authors or through adjudication by a fourth review author. Abstracts, editorials, conference proceedings and clinical trial registrations were excluded.

Observations

Yoga is a nonpharmacological, cost-effective, and safe intervention associated with several health benefits. Originating in ancient India, this vast discipline consists of postures (asanas), breathing techniques (pranayama), meditation (dhyana/dharana), and relaxation. Studies have demonstrated yoga’s ability to bolster innate immunity and to inhibit cytokine release syndrome. As an intervention, yoga has been shown to improve mental health, as it alleviates anxiety, depression, and stress and enhances mindfulness, self-control, and self-regulation. Yoga has been correlated with numerous cardioprotective effects, which also may play a role in COVID-19 by preventing lung and cardiac injury.

Conclusion and relevance

This review paves the path for further research on yoga as a potential intervention for enhancing innate immunity and mental health and thus its role in prevention and adjunctive treatment in COVID-19.

Effects of Different Exercise Therapies on Balance Function and Functional Walking Ability in Multiple Sclerosis Disease Patients-A Network Meta-Analysis of Randomized Controlled Trials

The objective of this research is to assess the effects of seven different exercise therapies (aquatic exercise, aerobic exercise, yoga, Pilates, virtual reality exercise, whole-body vibration exercise, and resistance exercise) on the balance function and functional walking ability of multiple sclerosis disease patients. Materials and Methods: The effects of different exercise interventions on the balance function and functional walking ability in people with multiple sclerosis were assessed by searching five databases: PubMed, Embase, Cochrane Library, Web of Science, and CNKI; only randomized controlled trials were included. The included studies were assessed for risk of bias using the Cochrane assessment tool. Results: The RCTs were collected between the initial date of the electronic databases’ creation and May 2022. We included 31 RCTs with 904 patients. The results of the collected data analysis showed that yoga can significantly improve patients’ BBS scores (SUCRA = 79.7%) and that aquatic exercise can significantly decrease patients’ TUG scores (SUCRA = 78.8%). Conclusion: Based on the network meta-analysis, we suggest that although each type of exercise is useful, yoga, virtual reality training, and aerobic training are more effective in improving the balance function of people with MS; aquatic exercise, virtual reality training, and aerobic training are more effective in improving the functional walking ability of people with MS.

Effects of yoga-based interventions on cognitive function in healthy older adults: A systematic review of randomized controlled trials

BACKGROUND

The world's elderly population is growing. Physical activity has positive effects on health and cognition, but is decreasing among the elderly. Interest in yoga-based exercises has increased in this population, especially as an intervention targeting balance, flexibility, strength, and well-being. Recent interest has arisen regarding yoga's potential benefits for cognition.

OBJECTIVE

To systematically review evidence from randomized controlled trials (RCTs) examining the effects of yoga-based interventions on cognitive functioning in healthy adults aged ≥60. A secondary aim was to describe intervention characteristics and, where possible, the extent to which these influenced study outcomes.

METHOD

The review was conducted in accordance with PRISMA guidelines. Searches were performed from inception to June 2020 using the following electronic databases: (1) PubMed (NLM); (2) Embase (Elsevier); (3) Cochrane Central (Wiley); (4) PsycINFO (EBSCOhost); and (5) Cinahl (EbscoHost).

INCLUSION CRITERIA

RCTs of yoga-based interventions assessing cognition in healthy adults ≥60 years. Risk of bias was assessed using the revised Cochrane risk of bias tool.

RESULTS

A total of 1466 records were initially identified; six studies (5 unique trials) were included in the review. Four of the six articles reported significant positive effects of yoga-based interventions on cognition, including gross memory functioning and executive functions. Intervention characteristics and assessment methods varied between studies, with a high overall risk of bias in all studies.

CONCLUSION

Yoga-based interventions are associated with improvements in cognition in healthy older adults. Adequately powered RCTs with robust study designs and long-term follow-ups are required. Future studies should explicitly report the intervention characteristics associated with changes in cognitive function.

Executive Function and Diabetes: A Clinical Neuropsychology Perspective

Objective

Diabetes is a global public health concern. Management of diabetes depends on successful implementation of strategies to alleviate decline in executive functions (EFs), a characteristic of diabetes progression. In this review, we describe recent research on the relationship between diabetes and EF, summarize the existing evidence, and put forward future research directions and applications.

Methods

Herein, we provide an overview of recent studies, to elucidate the relationship between DM and EF. We identified new screening objectives, management tools, and intervention targets for diabetes management. We also discuss the implications for clinical practice.

Results

In both types 1 and 2 diabetes mellitus (DM), hyperglycemia substantially impairs EF in people of all age groups and ethnicities. Hypoglycemia can similarly impair EF. Interestingly, a decline in EF contributes to DM progression. Glucose dysregulation and EF decline exacerbate each other in a vicious cycle: poor blood glucose control, impaired EF, diabetes management task failure, then back to poor blood glucose control. Many pathophysiological indexes (e.g., obesity, metabolic index, inflammatory and immune factors), neuropsychological indexes (e.g., compliance, eating habits, physical exercise, sleep, and depression), and genetic factors are changed by this pathological interaction between DM and EF. These changes can provide insight into the pathophysiological mechanisms of diabetes-related EF decline.

Conclusion

Further studies, including large-scale prospective and randomized controlled trials, are needed to elucidate the mechanism of the interaction between diabetes and EF and to develop novel strategies for breaking this cycle.

Mitigating the Antecedents of Sports-related Injury through Yoga

Context:

Injury risk among athletes is an epidemic. The psychological and physical loads imposed on athletes through psychosocial stressors and training regimens significantly increase athletes' injury risk.

Aims:

This feasibility study assessed whether a 10-week yoga intervention could be implemented successfully and mitigated antecedents of sports injury.

Methods:

Using a prospective, nonexperimental design, 31 male soccer players attending a college in the Pacific Northwest enrolled in the yoga intervention. The Recovery-Stress Questionnaire for Athletes (RESTQ-Sport) was completed at three time-points before and after the yoga intervention. The RESTQ-Sport scales, identified as strongest predictors for injury, were hypothesized to be mitigated through yoga.

Results:

Two stress-related scales were significant in the hypothesized direction: injury and fatigue. The general recovery scale, General Well-Being, was significant at one time-point, but in the opposite direction as hypothesized.

Conclusions:

Positive findings are discussed and explanations for unexpected changes are explored, along with study limitations. Results suggest that yoga can be successfully integrated into the athletic program of soccer players and provisionally support the potential of a yoga intervention to mitigate two significant antecedents of injury, namely, perception of propensity to sustain injury and generalized fatigue.

Mindfulness Training for Improving Attention Regulation in University Students: Is It Effective? and Do Yoga and Homework Matter?

The present study examined the effects of mindfulness training on attention regulation in university students and whether the potential benefits of implementation are influenced by the yoga component of mindfulness-based interventions (MBIs) and/or by MBI homework practice. In a non-randomized trial with pre- and post-assessments, n = 180 university students were allocated to either mindfulness training (experimental groups), awareness activities (active control group), or no training (passive control group). Mindfulness was taught through two MBIs, one including yoga and the other excluding yoga. Attention regulation was operationalized via behavioral indicators, namely sustained attention, cognitive flexibility, cognitive inhibition, and data-driven information processing. With the exception of speed in a cognitive flexibility task, the results indicated no systematic or differential advantage arising from mindfulness training, with or without yoga, regarding the aspects of attention regulation. There was no consistent influence of homework quantity or quality. The implications for mindfulness training in academic contexts are discussed.

Yoga to prevent mobility limitations in older adults: feasibility of a randomized controlled trial

Background

The loss of mobility during aging impacts independence and leads to further disability, morbidity, and reduced life expectancy. Our objective was to examine the feasibility and safety of conducting a randomized controlled trial of yoga for older adults at risk for mobility limitations.

Methods

Sedentary older adults (n = 46; age 60–89) were recruited and randomized to either yoga or a health education comparison group. Yoga sessions (60-min) occurred 2x weekly, and 90-min health education sessions occurred weekly, for 10 weeks. The primary outcomes were recruitment rate, intervention attendance, and retention at assessments. Adverse event rates and participant satisfaction were also measured. Physical performance measures of gait, balance, and strength and self-report outcome measures were administered at baseline and 10-weeks.

Results

Recruitment lasted 6 months. Retention of participants at the 10-week follow-up was high (89% - performance measures; 98% - self-report questionnaires). Attendance was good with 82% of yoga and 74% of health education participants attending at least 50% of the sessions. No serious adverse events were reported. Patient satisfaction with the interventions was high. The mean effect size for the physical performance measures was 0.35 with some over 0.50. The mean effect size for self-report outcome measures was 0.36.

Conclusions

Results indicate that it is feasible to conduct a larger RCT of yoga for sedentary older adults at risk for mobility problems. The yoga and comparison interventions were safe, well accepted, and well attended. Effect sizes suggest yoga may have important benefits for this population and should be studied further.

Trial Registration

ClinicalTrials # NCT03544879; Retrospectively registered 4 June, 2018.

Breath of Life: The Respiratory Vagal Stimulation Model of Contemplative Activity

Contemplative practices, such as meditation and yoga, are increasingly popular among the general public and as topics of research. Beneficial effects associated with these practices have been found on physical health, mental health and cognitive performance. However, studies and theories that clarify the underlying mechanisms are lacking or scarce. This theoretical review aims to address and compensate this scarcity. We will show that various contemplative activities have in common that breathing is regulated or attentively guided. This respiratory discipline in turn could parsimoniously explain the physical and mental benefits of contemplative activities through changes in autonomic balance. We propose a neurophysiological model that explains how these specific respiration styles could operate, by phasically and tonically stimulating the vagal nerve: respiratory vagal nerve stimulation (rVNS). The vagal nerve, as a proponent of the parasympathetic nervous system (PNS), is the prime candidate in explaining the effects of contemplative practices on health, mental health and cognition. We will discuss implications and limitations of our model.

A Physician's Guide to Recommending Yoga

The popularity of yoga in the United States and across the globe has been steadily increasing over the past several decades. The interest in yoga as a therapeutic lifestyle tool has also grown within the medical community during this time. However, the wide range of styles available to the public can make it difficult for patients and physicians alike to choose the one that will offer the most benefit. This guide was created to assist physicians in making informed recommendations for patients practicing yoga in the community. When the most suitable style is selected, yoga can be an extremely useful lifestyle tool for patients seeking to improve fitness and develop a mindfulness-based practice.

The Effects of Physical Exercise and Cognitive Training on Memory and Neurotrophic Factors

This study examined the combined effect of physical exercise and cognitive training on memory and neurotrophic factors in healthy, young adults. Ninety-five participants completed 6 weeks of exercise training, combined exercise and cognitive training, or no training (control). Both the exercise and combined training groups improved performance on a high-interference memory task, whereas the control group did not. In contrast, neither training group improved on general recognition performance, suggesting that exercise training selectively increases high-interference memory that may be linked to hippocampal function. Individuals who experienced greater fitness improvements from the exercise training (i.e., high responders to exercise) also had greater increases in the serum neurotrophic factors brain-derived neurotrophic factor and insulin-like growth factor-1. These high responders to exercise also had better high-interference memory performance as a result of the combined exercise and cognitive training compared with exercise alone, suggesting that potential synergistic effects might depend on the availability of neurotrophic factors. These findings are especially important, as memory benefits accrued from a relatively short intervention in high-functioning young adults.

The Roles of Exercise and Yoga in Ameliorating Depression as a Risk Factor for Cognitive Decline

Currently, there are no effective pharmaceutical treatments to reduce cognitive decline or prevent dementia. At the same time, the global population is aging, and rates of dementia and mild cognitive impairment (MCI) are on the rise. As such, there is an increasing interest in complementary and alternative interventions to treat or reduce the risk of cognitive decline. Depression is one potentially modifiable risk factor for cognitive decline and dementia. Notably, exercise and yoga are two interventions known to both reduce symptoms of depression and improve cognitive function. The current review discusses the efficacy of exercise and yoga to ameliorate depression and thereby reduce the risk of cognitive decline and potentially prevent dementia. Potential mechanisms of change, treatment implications, and future directions are discussed.

Yoga research review

This paper is a review of empirical studies, review and meta-analysis publications on yoga from the last few years. The review includes demographics/prevalence of yoga as a practice, bibliometric analyses of the yoga publications and the use of yoga for physical fitness and cognitive function. Most of the studies reviewed here involve yoga effects on psychiatric and medical conditions. These include pregnancy, prenatal and postpartum depression; stress, PTSD, anxiety, and obesity; cardiovascular conditions including hypertension; pain syndromes including arthritis, headaches and low back pain; autoimmune conditions including asthma, type II diabetes and multiple sclerosis; immune conditions including HIV and breast cancer; and aging problems including balance, osteoporosis and Parkinson's. The methods and results of those studies are briefly summarized along with their limitations and suggestions for future research. Basically yoga has been more effective than control and waitlist control conditions, although not always more effective than treatment comparison groups such as other forms of exercise. More randomized controlled studies are needed in which yoga is compared to active exercise groups. Having established the physical and mental health benefits of yoga makes it ethically questionable to assign participants to inactive control groups. Shorter sessions should be investigated for cost-effectiveness and for daily practice. Multiple physical and physiological measures need to be added to the self-report research protocols and potential underlying mechanisms need to be further explored. In the interim, the studies reviewed here highlight the therapeutic effects of yoga, a practice that could come to be called yoga therapy.

Microbiota and Neurological Disorders: A Gut Feeling

In the past century, noncommunicable diseases have surpassed infectious diseases as the principal cause of sickness and death, worldwide. Trillions of commensal microbes live in and on our body, and constitute the human microbiome. The vast majority of these microorganisms are maternally derived and live in the gut, where they perform functions essential to our health and survival, including: digesting food, activating certain drugs, producing short-chain fatty acids (which help to modulate gene expression by inhibiting the deacetylation of histone proteins), generating anti-inflammatory substances, and playing a fundamental role in the induction, training, and function of our immune system. Among the many roles the microbiome ultimately plays, it mitigates against untoward effects from our exposure to the environment by forming a biotic shield between us and the outside world. The importance of physical activity coupled with a balanced and healthy diet in the maintenance of our well-being has been recognized since antiquity. However, it is only recently that characterization of the host-microbiome intermetabolic and crosstalk pathways has come to the forefront in studying therapeutic design. As reviewed in this report, synthetic biology shows potential in developing microorganisms for correcting pathogenic dysbiosis (gut microbiota-host maladaptation), although this has yet to be proven. However, the development and use of small molecule drugs have a long and successful history in the clinic, with small molecule histone deacetylase inhibitors representing one relevant example already approved to treat cancer and other disorders. Moreover, preclinical research suggests that epigenetic treatment of neurological conditions holds significant promise. With the mouth being an extension of the digestive tract, it presents a readily accessible diagnostic site for the early detection of potential unhealthy pathogens resident in the gut. Taken together, the data outlined herein provide an encouraging roadmap toward important new medicines and companion diagnostic platforms in a wide range of therapeutic indications.